8936/1 Gastrointestinal pacemaker cell tumor

Related terms

Definitions

Stomach

ICD-O-3 topography code:

C16

The term gastrointestinal stromal tumour (GIST) is used for a specific group of tumours comprising the majority of gastrointestinal mesenchymal tumours, including those previously termed leiomyoma, cellular leiomyoma, leiomyoblastoma and leiomyosarcoma 1

; they are the most common primary mesenchymal tumour of the gastrointestinal tract GIST spans a clinical spectrum from benign to malignant; it has been estimated that about 25% of gastric GISTs (not counting minimal incidental tumours) are clinically malignant. The median age at manifestation is 60-65 years. GIST are KIT-expressing and KIT signaling-driven mesenchymal tumors respond favourably to treatment with the KIT tyrosine kinase inhibitor imatinib mesylate / gleevec 3

The term gastrointestinal stromal tumour (GIST) is used for a specific group of tumours comprising the majority of gastrointestinal mesenchymal tumours, including those previously termed leiomyoma, cellular leiomyoma, leiomyoblastoma and leiomyosarcoma 4

The term gastrointestinal stromal tumour (GIST) is used for a specific group of tumours comprising the majority of gastrointestinal mesenchymal tumours, including those previously termed leiomyoma, cellular leiomyoma, leiomyoblastoma and leiomyosarcoma 7

GISTs of the colon and rectum
GISTs are very rare in the colon (about 1% of all GISTs) and have a predilection for the sigmoid. However, microscopic GISTs have been detected in 0.2% of retrospectively examined sigmoid-colon resections. Rectal GISTs comprise 4% of all GISTs and occur in any segment. These tumours vary from incidentally detected small mural nodules to large, complex pelvic masses that can cause intestinal obstruction or gastrointestinal bleeding. Those with anterior extension can abut the prostate gland and clinically simulate prostate cancer 9

.
Most colonic GISTs are advanced tumours when detected, and have a poor prognosis. The behaviour of rectal GISTs is often aggressive, and even small tumours of < 2 cm in size with mitotic activity can recur and metastasize. Pelvic extension and liver metastasis is common, and bone metastases may develop more often than in gastric and small-intestinal GISTs13

The term gastrointestinal stromal tumour (GIST) is used for a specific group of tumours comprising the majority of gastrointestinal mesenchymal tumours, including those previously termed leiomyoma, cellular leiomyoma, leiomyoblastoma and leiomyosarcoma 14

GISTs are very rare in the oesophagus and comprise 10?20% of the combined group of smooth-muscle and stromal tumours. Most are clinically detected as intraluminal distal oesophageal masses causing dysphagia, but externally extending oesophageal GISTs can manifest as mediastinal tumours.
Occasional examples have been incidentally detected during radiological screening or surveillance studies, and such tumours can have a good prognosis, an exception among this group of tumours, among which sarcomas predominate 16

The term gastrointestinal stromal tumour (GIST) is used for a specific group of tumours comprising the majority of gastrointestinal mesenchymal tumours, including those previously termed leiomyoma, cellular leiomyoma, leiomyoblastoma and leiomyosarcoma 17